1. Field of the Invention
The present invention relates to anti-whiplash systems for use in motor vehicles and, more specifically, to an indicator sensor that alerts a vehicle occupant when an anti-whiplash system has been activated.
2. Technical Background
Whiplash related injuries are caused by the rapid acceleration of a vehicle occupant's head and cervical spine in opposite directions from one another. This typically happens in rear end, and sometimes front end, vehicle collisions. In a rear end collision, for example, an occupant's torso, being supported by the seatback, is accelerated forward, while the occupant's neck and head are quickly accelerated toward the seatback and head rest. Because of the weight of a person's head compared with the ability of the neck muscles to support it, the neck flexes posteriorly such that the head strikes the head rest before the neck. Once the occupant's head strikes the headrest, it is usually then accelerated away from the headrest as the occupant's torso reverses direction and accelerates toward the seatback. The acceleration of the head and torso in opposite directions greatly stresses the cervical spine. Typical whiplash related injuries may include fractured or dislocated vertebrae, torn ligaments, and may even result in death. Even in slow velocity impacts, the damage can be severe, oftentimes not manifesting itself until some time after the accident.
There are many devices implemented to prevent injury as occupants are thrown forward in a vehicle, including seat belts and airbags. However, there are not many devices that effectively reduce injuries as an occupant is accelerated toward the seatback. Headrests are provided, but typically fail to offer adequate protection. This is largely due to their location relative to the occupant's head and neck. Optimally, the center of the headrest should be positioned behind the head and inline with the center of gravity of the occupant's head. Too often, the headrest is too high, which forces the occupant's head downward during a collision. Alternatively, the headrest may be too low, which results in the occupant's head sliding up and over the top of the headrest which can result in hyper extension of the cervical spine which results in severe injuries.
One device for protecting a vehicle occupant during a collision is an anti-whiplash mechanism built into the vehicle seat. Such a device allows the seat to absorb some of the impact rather than translate the forces directly to the occupant. This is accomplished by designing the connection between the seatback and the seating surface to allow the seatback to slide rearward as an occupant is thrown against it. The mechanism utilizes two substantially flat plates, which overlap and are pivotally connected. One plate is attached to the seating surface, while the other is attached to the seatback. When sufficient force is applied to the seatback, the two plates are allowed to slide relative to one another such that the seatback slides rearward relative to the seating surface.
Once the anti-whiplash mechanism has been activated, the mechanism requires professional inspection and maintenance to restore the seat to its proper position and reset the anti-whiplash mechanism. However, because significant forces can be involved even during low velocity impacts, a vehicle occupant does not always know when an anti-whiplash mechanism has been activated, and therefore may not realize the mechanism is no longer able to provide anti-whiplash protection.
Additionally, other vehicle seat systems may be inplemented in a vehicle seat to further protect an occupant. These systems include systems such as All Belts to Seat (ABTS) systems, and Occupant Weight Sensors (OWS), and other similar systems. These vehicle seat systems are generally comprised of additional components. A vehicle seat may experience stresses which weaken installed vehicle systems or components of vehicle systems such that the vehicle system will no longer perform properly. However, the occupant may have no visual, audible, or other indication that the vehicle seat system has experienced stress beyond the design specifications of the vehicle seat system.
Accordingly, what is needed in the art is a device which notifies a vehicle occupant when a vehicle seat system such as an anti-whiplash device has been activated allowing the vehicle owner to have the vehicle professionally serviced to insure that the anti-whiplash mechanism is functioning properly. It would be an advancement in the art to provide such a device which provides a visible signal to the vehicle occupant. It would be another advancement in the art to provide such a device and visual signal in the form of a warning light on the dashboard of the vehicle. It would be a further advancement in the art to provide such a device which is inexpensive, easily fabricated, and conveniently installed in a vehicle.